A newly developed “nanosponge” has the ability to soak up toxins released by bacterial infections and venom from the bloodstream

Engineers at the University of California, San Diego have developed a “nanosponge”, a polymer structure wrapped in the membrane from a red blood cell. The sponge is capable of soaking up toxins release by both venoms and bacterial infections such as MRSA and E. coli. The sponge has been studied in mice so far and proven capable of neutralizing pore-forming toxins which destroy cells by poking holes in their cell membranes. Traditional anti-toxins need to be specifically engineered to combat individual toxins, but the nanosponge is unique in being applicable for a broad range of different toxins.

The nanosponge has proven to be extremely effective at combating the toxins: Laboratory mice were exposed to a lethal dose of alpha-haemolysin toxin from MRSA and those who had been previously inoculated with nanosponges exhibited an 89% survival rate. Even the mice who were injected with nanosponges after the fact had good result, with 44% surviving. "This is a new way to remove toxins from the bloodstream," said Liangfang Zhang, nanoengineering professor at the UC San Diego, who hopes to develop the new technology into approved therapies.

The nanosponge

The nanosponge has a diameter of about 85 nanometers, about one hundredth the size of a red blood cell. The mention of red blood cells is significant, because the function of the sponge is highly dependent on them: The nanosponge is wrapped in bits of cell membrane from red blood cells, something which has two functions: First, it keeps the immune system from ridding itself of the sponges. In addition, because many toxins specifically target red blood cells, the nano sponge acts as a decoy, attracting toxins to it instead of your body. Normally, these toxins would poke holes in the cell membranes of red blood cells, thereby letting ions into the cell and killing it. Instead, the nanosponge simply absorbs them. After 40 hours or so, the sponges are naturally processed by the liver with no ill effects, even after absorbing the toxins.

During the study, releasing toxins and nanosponges at a ratio of 70:1 completely neutralized the toxins with no discernible damage to the lab mice. The researchers are now saying they want to pursue clinical trials.